2.08 Add decimals
Introduction
When we add whole numbers, such as 82+35, we use the standard algorithm, also known as the vertical algorithm, to help us solve the addition.
We start by adding the values in the ones column, remembering to carry in to the tens column where necessary, and then by adding the values in the tens column, and so on. \begin{array}{crrrr} & &\text{Hundreds} &\text{Tens} & \text{Ones} \\ & & & 8 & 2 \\ &+& & 3 & 5 \\ \hline & & 1& 1 & 7 \\ \hline \end{array}
We can see when we added the values in the tens column, we carry over into the hundreds column, giving us a final answer of 117.
Ideas
Add decimal numbers
When adding numbers with decimals we can use the exact same approach. The following video shows us how to add decimal numbers using the standard algorithm:
The standard algorithm in adding numbers with decimals may include the following steps.
Line up the decimal points vertically, filling in any 0's where place value holders are needed.
Add the numbers as if they were whole numbers.
Place the decimal point in the sum so that it lines up vertically with the numbers being added.
Examples
Example 1
Find 3.8+4.6 giving your answer as a decimal.
Example 2
Add: 2.86+1.6
Adding decimals uses the same process as we use for whole numbers, but we need to consider the value of the digits and where our decimal point needs to be.